Apparatus and method for molding cup-shaped bodies



Sept. 22, 1964 L. J. GEHL 3,149,375

APPARATUS AND METHOD FOR MOLDING CUP-SHAPED BODIES Filed April 18, 19612 Sheets-Sheet 1 1 ll lllll x7, 29 4 m: 23 2a INVENTOR. inn/E z/vcs J65/11.

ZZM

Jrro/Q/VEY Sept. 22, 1964 L. J. GEHL 3,149,375

APPARATUS AND METHOD FOR MOLDING CUP-SHAPED BODIES Filed April 18, 19612 Sheets-Sheet 2 Z I. ,2. 5 6 l INVENTOR. [A W/E'E/VCE J. 65/11.

AJ A-t-L IQ United States Patent 3,149,375 APPARATUS AND METHOD FDRMOLDING CUP-SHAPED BODIES Lawrence J. Gehl, Corning, N.Y., assignor toCorning Glass Works, Corning, N.Y., a corporation of New York Filed Aug.18, 1961, Ser. No. 132,335 7 Claims. (Cl. 18-165) This invention relatesto apparatus for and the method of molding a unitary cup-shaped bodywith wires comolded in and passing generally horizontally through thebase of the body from an external side surface to the inside surface ofthe base.

Attempts to produce a satisfactory and economical housing forsemiconductor devices resulted in the design of a cup-shaped base inwhich a plurality of conducting lead wires were to be comolded in andextended horizontally through the sidewall of the base to form a unitarystructure, as disclosed in copending US. patent application Serial No.76,046 by William C. Smith, filed December 15, 1960, and assigned to theassignee of this application. In manufacturing the comolded base andwires, it was desired to make it from granular or powdered ceramicmaterial, either vitreous or crystalline, and which is known to be aneasily molded material. However, no known molding apparatus was foundcapable of manufacturing this cup-shaped base from powdered ceramicmoldable material with horizontally comolded wires there- It is,accordingly, an object of this invention to provide an apparatus and amethod for comolding wires and powdered or granular moldable material toform a unitary cup-shaped body with the wires passing generallyhorizontally through the base of the body from an external side surfaceto the inside surface of the base.

While the present invention is especially useful for molding the unitarycup-shaped articles from powdered ceramic material, it can also beemployed for forming a similar article from other suitable powdered orgranular material, such as metal, carbon and the like, when so desired.

The present invention may be best understood by reference to theaccompanying drawings wherein:

FIG. 1 is a fragmentary, sectional, front elevation of a preferredembodiment of a molding press assembly according to the presentinvention,

FIG. 2 is a sectional plan view of the open-top die block taken on line22. of FIG. 1,

FIG. 3 is a fragmentary vertical section of the mold assembly showingthe moldable material and wires at the beginning of the compressionstroke,

FIG. 4 is a fragmentary vertical section of the mold assembly showingthe molded material and wires at the end of the compression stroke.

Referring to FIGS. 1 and 2, the molding assembly comprises a die block 1with a vertical bore defined by the cylindrical wall 2. The top surface3 of die block 1 contains grooves 4 communicating with the verticalbore. An annular mold cavity is defined by the cylindrical wall 2 of thevertical bore, core member 5 arid axial- "ly movable surrounding means,or tubular rarn 6.

A threaded lower end of core member 5 extends through hollow structure7, formed in a conventional molding press frame (not shown), and isconnected to air cylinder 8. Air cylinder 8 is suitably mounted on thebase of the molding press frame (not shovm). Adjustable nut 9 is mountedon the threaded portion of core member 5 passing through the hollow instructure 7. Nut 9 is adjusted to position the top end of core member 5at the bottom level of grooves 4 when nut 9 is forced "ice upwardly byair cylinder 8 and against surface 10 on structure '7.

Adjustable nut 11 is also mounted on the threaded portion of core member5 passing through the hollow in s ructure 7, but below nut 9. If it isdesired to maintain core member 5 stationary during the compressionstroke, nut 11 is adjusted downward on core member 5 until nut 9 isforced against surface 10 and nut 11 is pressed against surface 12 ofstructure 7. Where it is desired'to downwardly displace core member 5 alimited distance during the compression stroke, nut 11 is adjustedupwardly a suitable distance away from surface 12 when nut 9 is forcedagainst surface 10 by air cylinder 8. The latter position of nut 11 isindicated by the dotted line 13.

Tubular ram 6 has a rigidly connected tubular extension 14-, whichsurrounds core member 5. An adjustable nut 15 is mounted on an upperthreaded portion of extension 14. Nut 15 normally rests on thecylindrical supporting structure 32, which surrounds extension 14 and isa portion of the molding press frame (not shown). The top end of tubularram 6 is normally positioned at an appropriate level below the top endof core member 5 by adjusting nut 15.

Tubular ram 6 and nut 15 are resiliently maintained in their normalposition by means of springs 16, which are arranged around support rods17. The upper ends of rods 17 are rigidly attached to the underside ofpress table 18, which rigidly holds die block 1 in its upper surface.The lower ends of rods 17 pass through holes in plate 19. Plate 19 isarranged around extension 14 and rests on the upper surface of nut 15.Springs 16 engage the bottom surface of press table 18 and the topsurface of plate 19, thereby urging nut 15 downwardly to its normal restposition.

Circular die member 2t) has a passage therethrough defined bycylindrical wall 21, the diameter of which is the same as that of thevertical bore in die block 1. Die member 212 is arranged over topsurface 3 of die lock 1 so that cylindrical wall 21 is in register withcylindrical wall 2. The passage in die member 29 provides increased moldcavity capacity for moldable material to form the base of the cup-shapedbody.

One convenient means of rigidly positioning die member 21 is provided bythe raised peripheral portion 22 on the top surface of die block 1.Raised portion 22 has a surface 23 adapted to receive and rigidlyposition die member 2f; on top of recessed surface 3. However, it willbe recognized by those skilled in the art that other suitablepositioning means may be utilized if desired.

Plunger 24 comprises a conventional solid cylinder adapted to enter theupper part of the mold cavity, as defined by the passage in die member20, by conventional cam operating means (not shown) for compression of acharge of moldable material placed in the mold cavity.

When additional compression is desired in the annular portion of themold cavity, tubular ram 6 can be advanced upwardly simultaneously withthe downward advance of plunger 24 within the mold cavity. For thispurpose, adjustable nut 25 is mounted on the lower threaded portion ofextension 14. Conventional cam operated lever arms 26 engage the bottomsurface of nut 25 on two oposite sides to effect the upward movement ofram 6 during compression.

Means for ejecting the molded body from the mold cavity comprises anadjustable nut 27 mounted on the upper threaded portion of extension 14and conventional cam operated lever arms 28, the latter engaging thebottom surface of nut 27 on two opposite sides to effect the upwardmovement of ram 6 after the compression cycle is completed and plunger24 is withdrawn from the mold cavity. Nut 27 is adjusted so that the topend of ram 6 is advanced upwardly to at least the level of surface 3.

Suitable arrangement of conventional cam operating means for eifectingappropriate motions to plunger 24 and ram 6, and for timing the sequenceof the motions, may be substantially as taught in US. Patent 2,499,980.

The operation of the molding press assembly of the invention is bestdescribed in connection with the novel cornolding method for forming theabove described unitary cup-shaped body. Initially, die member 20 isremoved by suitable means (for example, it can be removed manually byproviding a handle means on the top surface 29 of die member 20). Aircylinder 8 is actuated to position the top of core member at the bottomlevel of grooves 4. Although core member 5 can be maintained stationaryduring compression, it is preferred to allow a small downwarddisplacement by adjusting nut 12 upward an appropriate distance to aposition represented by dotted line 13. Nut 15 is adjusted to providethe proper amount of fill space in the annular portion of the moldcavity that will yield the desired height of the compressed cup-shapedbody. When it is desired to give greater strength to the annular wall ofthe cup-shaped body, lever arms 26 are connected to conventional camoperating means to provide upward advancement of ram 6 duringcompression and nut 25 is adjusted so that during compression the topend of core member 5 remains the desired distance above the top end ofram 6 to yield the desired height of the annular wall of the cup-shapedbody.

The first step of the method consists of positioning straight pieces ofwire horizontally through radially spaced openings in the sidewall of anopen top mold and in a plane intermediate the top and bottom of thecavity formed by the mold. Thus, the straight pieces of wire are placedin grooves 4 and die member is replaced on top of surface 3.

Next, the wire pieces are extended horizontally into the cavity so thattheir innermost ends rest on and are supported by the core member 5.This step may be conveniently performed simultaneously with the firststep by providing wire pieces of appropriate length to occupy the entirelength of grooves 4 from surface 23 and to extend onto the top surfaceof core member 5. When utilizing this method to produce a semiconductorhousing base as disclosed in the aforementioned application Serial No.76,046, the innermost ends of the wire pieces resting on core member 5are suitably spaced apart as shown in the copending application.

When the positioning and extending of the wire pieces is completed, theentire mold cavity (including the annular portion) is filled with acharge of granular molding material by conventional means (for example,as shown in US. Patent 2,499,980) and customarily up to the level ofsurface 29. Then the charge of molding material is compressed within thecavity and, preferably concurrently therewith, the portion of the wirepieces within the cavity are downwardly displaced so that they passthrough the base of the cup-shaped body generally diagonally from spacedpoints near the bottom edge of the external side surface of the base tothe inner surface of the base and thence flush with the inner surface.

The preferred concurrent compressing and displacing steps are bestunderstood by referring to FIGS. 3 and 4. At the beginning of thecompression stroke, as shown in FIG. 3, wire pieces 30 are in theirinitial position and the entire mold cavity is filled with granularmoldable material 31. Plunger 24 is on the down stroke and is justentering the passage in die member 20. At this point, tubular ram 6 isjust beginning its upward advancement. FIG. 4 shows plunger 24 and ram 6at the end of their compression strokes with the resultant compressionof the moldable material 31 into a cup-shaped body and with theconcurrent displacement of the wire pieces 30 to the aforementionedgenerally diagonal position within the base of the body. In effectingthe concurrent compression and displacement, core member 5 has beendisplaced downwardly to its lower limit as determined by nut 12 andagainst the 4- resilient upward pressure effected by air cylinder 8. Ifthe downward displacement of the wire pieces is not desired, core membr5 should be maintained stationary.

At the end of the compression stroke, the pressure effected by aircylinder 3 is released before plunger 24 is withdrawn to prevent coremember 5 from breaking through the central portion of the base of thecup-shaped body as a result of the annular wall of the cup-shaped bodysticking to the mold cavity wall. Then plunger 24 is withdrawn and diemember 20 is removed. Ejection of the molded, unitary, cup-shaped bodyis subsequently effected by causing lever arms 28 to upwardly advanceram 6.

The assembly is made ready for molding another body by lowering leverarms 26 and 28 to their initial position whereby ram 6 is returned toits normal position by means of spring 16. Air cylinder 8 is againactuated to position the top of core member 5 at the bottom level ofgrooves 4.

While the foregoing apparatus and method have been described with theuse of a plurality of grooves 4 and a similar plurality of wire pieces39, it will be appreciated that only one groove and one wire piece maybe provided, if desired for any particular purpose. In the preferredembodiment for producing a semiconductor housing base, as best shown inFIG. 2, three grooves, each spaced substantially radially from anotherone, are provided for three wire pieces to be comolded in the unitarycup-shaped body.

The depth and width of grooves 4 are preferably proportioned to closelyfit the cross-sectional dimensions of the desired wire pieces used.

Any suitable combination of granular moldable material and metal oralloy can be used for the body and wire pieces, respectively. Apreferred combination used for the semi-conductor housing base is glassof the composition disclosed in copending U.S. patent application SerialNo. 824,369 by R. H. Dalton, filed July 1, 1959, and assigned to theassignee of this application, which is ground to a finely dividedpowder, and platinum metal in the form of flat thin wire.

It should be understood that the illustrated embodiments of theinvention may be varied in their details within the spirit of theinvention. Accordingly, it is intended that the scope of the presentinvention be limited only by the appended claims.

What is claimed is:

1. In a molding press, an assembly useful in pressing from moldablegranular material a unitary cup-shaped body with at least one wirepassing through the base of said body generally horizontally from theexternal side surface of said base to the inner surface of said base andthence flush with said inner surface, comprising. a stationary die blockhaving a vertical bore therethrough and at least one groove in the topsurface of said block extending substantially radially from andcommunicating with said bore, said groove adapted to loosely hold apiece of wire in predetermined position with a portion extending intosaid bore, means positioned in and cooperating with said bore to definean annular mold cavity comprising a core member with means for normallypositioning the topend of said core member at the bottom level of saidgroove to thereby form a support for the end of the extending portion ofsaid wire and axially movable surrounding means with means for normallypositioning the top end of said surrounding means at a level below thetop end of said core member, means for restricting downward displacementof said core member and said axially movable sur rounding means duringcompression of said moldable material, means arranged over the top ofsaid die block for loosely holding said wire in said groove and having apassage therethrough of the diameter of said bore in register therewiththereby increasing the mold cavity capacity for moldable material toform said base, and means for compressing a charge of moldable materialand wire placed in said mold cavity.

2. The assembly of claim 1 including means for advancing upwardly saidsurrounding means during compression to a level where its top end isbelow the top end of said core member.

3. The assembly of claim 1 wherein the top surface of said die block hasa plurality of grooves communicating with and extending substantiallyradially from said bore.

4. The assembly of claim 3 having three grooves, each being spacedsubstantially radially 90 from another one of said grooves.

5. The assembly of claim 1 including means for advancing upwardly saidsurrounding means to at least the level of the top surface of said dieblock to eifect ejection of the molded body from the mold cavity.

6. The assembly of claim 1 including a raised peripheral portion on thetop surface of said die block surrounding and defining a recessedportion of said surface having said at least one groove therein, saidperipheral portion adapted to receive and rigidly position said meansarranged over the top of said die block on said recessed portion.

7. In a molding press, an assembly useful in pressing from moldablegranular material a unitary cup-shaped body with a plurality of wirespassing through the base of said body generally diagonally from spacedpoints near the bottom edge of the external side surface of said base tothe inner surface of said base and thence flush with said inner surface,comprising a stationary die block having a vertical bore therethroughand a plurality of grooves in the top surface of said blockcommunicating with and extending substantially radially from said bore,each of said grooves adapted to loosely hold a piece of wire inpredetermined position with a portion extending into said bore, meanspositioned in and cooperating with said bore to define an annular moldcavity comprising a resiliently, downwardly displaceable core memberwith means for normally positioning the top end of said core member atthe bottom level of said grooves to thereby form a support for the endsof the extending portions of said Wires and axially movable surroundingmeans with means for normally positioning the top end of saidsurrounding means at a level below the top end of said core member,means for restricting downward displacement of said core member andmeans for advancing upwardly said surrounding means during compressionof said moldable material to levels where the top end of said coremember remains above the top end of said surrounding member, meansarranged over the top of said die block for loosely holding said Wiresin said grooves and having a passage therethrough of the diameter ofsaid bore in register therewith thereby increasing the mold cavitycapacity for moldable material to form said base, means for compressinga charge of moldable material and wires placed in said mold cavity andfor concurrently depressing the extending portion of said wires to saidgenerally diagonal position with the depression of said core member ascompression of the charge is being effected, and means for advancingupwardly said surrounding means to at least the level of the top surfaceof said die block to efiect ejection of the molded body from the moldcavity.

References Cited in the file of this patent UNITED STATES PATENTS405,655 Baum June 18, 1889 1,120,291 Davis Dec. 8, 1914 1,609,427Queneau Dec. 7, 1926 1,648,721 Claus Nov. 8, 1927 1,813,576 KattwinkelJuly 7, 1931 1,914,004 Brasket June 13, 1933 1,922,527 Daniel Aug. 15,1933 2,166,205 Anderson July 18, 1939 2,821,748 Willi Feb. 4, 19583,009,578 Foote et a1. Nov. 21, 1961 FOREIGN PATENTS 1,129,497 FranceIan. 22, 1957

1. IN A MOLDING PRESS, AN ASSEMBLY USEFUL IN PRESSING FROM MOLDABLEGRANULAR MATERIAL A UNITARY CUP-SHAPED BODY WITH AT LEAST ONE WIREPASSING THROUGH THE BASE OF SAID BODY GENERALLY HORIZONTALLY FROM THEEXTERNAL SIDE SURFACE OF SAID BASE TO THE INNER SURFACE OF SAID BASE ANDTHENCE FLUSH WITH SAID INNER SURFACE, COMPRISING A STATIONARY DIE BLOCKHAVING A VERTICAL BORE THERETHROUGH AND AT LEAST ONE GROOVE IN THE TOPSURFACE OF SAID BLOCK EXTENDING SUBSTANTIALLY RADIALLY FROM ANDCOMMUNICATING WITH SAID BORE, SAID GROOVE ADAPTED TO LOOSELY HOLD APIECE OF WIRE IN PREDETERMINED POSITION WITH A PORTION EXTENDING INTOSAID BORE, MEANS POSITIONED IN AND COOPERATING WITH SAID BORE TO DEFINEAN ANNULAR MOLD CAVITY COMPRISING A CORE MEMBER WITH MEANS FOR NORMALLYPOSITIONING THE TOP END OF SAID CORE MEMBER AT THE BOTTOM LEVEL OF SAIDGROOVE TO THEREBY FORM A SUPPORT FOR THE END OF THE EXTENDING PORTION OFSAID WIRE AND AXIALLY MOVABLE SURROUNDING MEANS WITH MEANS FOR NORMALLYPOSITIONING THE TOP END OF SAID SURROUNDING MEANS AT A LEVEL BELOW THETOP END OF SAID CORE MEMBER, MEANS FOR RESTRICTING DOWNWARD DISPLACEMENTOF SAID CORE MEMBER AND SAID AXIALLY MOVABLE SURROUNDING MEANS DURINGCOMPRESSION OF SAID MOLDABLE MATERIAL, MEANS ARRANGED OVER THE TOP OFSAID DIE BLOCK FOR LOOSELY HOLDING SAID WIRE IN SAID GROOVE AND HAVING APASSAGE THERETHROUGH OF THE DIAMETER OF SAID BORE IN REGISTER THEREWITHTHEREBY INCREASING THE MOLD CAVITY CAPACITY FOR MOLDABLE MATERIAL TOFORM SAID BASE, AND MEANS FOR COMPRESSING A CHARGE OF MOLDABLE MATERIALAND WIRE PLACED IN SAID MOLD CAVITY.